1. Field of the Invention
The present invention relates to a liquid crystal display device that controls the orientation of liquid crystal molecules using a transversal electric field.
2. Description of the Related Art
Known liquid crystal display devices include an In-plane Switching (IPS) type liquid crystal display device that controls the orientation of liquid crystal molecules using an electric field parallel to the substrates that constitute the liquid crystal display device.
This liquid crystal display device comprises a pair of substrates arranged opposite each other at a predetermined gap, having been subjected to an aligning treatment in mutually parallel but opposite directions on each of the mutually opposed inner surfaces and, in the gap therebetween, a liquid crystal layer interposed substantially in parallel with the substrate surfaces, with the long axes of the liquid crystal molecules aligned in the direction of the aligning treatment. A pixel electrode in which a plurality of bent electrodes long and narrow in shape is formed in parallel at a distance from one another in a predetermined area for forming a single pixel is provided on the inner surface of one of the substrates of the pair of substrates, and an opposing electrode for generating an electric field that changes the orientation of the long axes of the liquid crystal molecules between the plurality of electrodes of the pixel electrode to an orientation that is substantially parallel to the substrate surfaces when voltage is applied between the opposing electrode and the pixel electrode is provided on the other substrate, in isolation from the pixel electrode.
This In-plane Switching (IPS) type liquid crystal display device generates an electric field parallel to the substrates that corresponds to display data between the pixel electrode and the opposing electrode. When an electric field is applied parallel to the substrate, the In-plane Switching (IPS) type liquid crystal display device controls on an inner surface substantially parallel with the substrate surfaces the orientation of the long axes of the liquid crystal molecules of a plurality of pixels comprising an area corresponding to the pixel electrode and opposing electrode, and displays an image.
Now, in the In-plane Switching (IPS) type liquid crystal display device, as described in Unexamined Japanese Patent Application KOKAI Publication No. 2002-182230, the plurality of bent electrodes of the first electrode is formed into a shape bent into a “<” shape to decrease the viewing angle dependability of the display and achieve a display having a wide viewing angle. That is, the orientation of the electric field parallel to the substrates that is generated between the opposing electrode and one of the electrodes of the two sections on either side of the bent section of the “<” shape, and the orientation of the electric field parallel to the substrates that is generated between the other linear section and the second electrode are made to differ from each other. With such an arrangement, the pixel electrode is formed so that the liquid crystal molecules are arranged in two different directions within each pixel.
However, in the In-plane Switching (IPS) type liquid crystal display device in which the plurality of electrodes of the first electrode are formed into a shape that is bent into a “<” shape, the problem arises that, when a strong electric field parallel to the substrates is generated, the orientation of the liquid crystal molecules within each pixel becomes non-uniform and, as a result of these pixels, display unevenness occurs.